Studies focusing on the effects of high-fiber diets, such as Mediterranean, vegetarian, and vegan diets, on patients affected by IBD, resulted in improvements in microbiome outcomes (increase in alpha diversity, increase in specific microbial population, etc.), in laboratory exams (reduction in C-reactive protein (CRP), reduction in fecal calprotectin, etc.), and IBD-specific outcomes (i.e., reduction in Mayo Score), as well as in an increase in SCFA levels [194]. Here, CRP is linked to irritable bowel syndrome.